Nano Archive

Unique Cellular Interaction of Silver Nanoparticles: Size-Dependent Generation of Reactive Oxygen Species

Carlson, C and Hussain, S. M. and Schrand, A. M. and Braydich-Stolle, Laura K. and Hess, K. L. and Jones, R. L. and Schlager, J. J. (2008) Unique Cellular Interaction of Silver Nanoparticles: Size-Dependent Generation of Reactive Oxygen Species. Journal of Physical Chemistry B, 112 (43). pp. 13608-13619. ISSN 10895647

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Official URL: http://dx.doi.org/10.1021/jp712087m

Abstract

The rapid advancement of nanotechnology has created a vast array of engineered nanomaterials (ENMs) which have unique physical (size, shape, crystallinity, surface charge) and chemical (surface coating, elemental composition and solubility) attributes. These physicochemical properties of ENMs can produce chemical conditions to induce a pro-oxidant environment in the cells, causing an imbalanced cellular energy system dependent on redox potential and thereby leading to adverse biological consequences, ranging from the initiation of inflammatory pathways through to cell death. The present study was designed to evaluate size-dependent cellular interactions of known biologically active silver nanoparticles (NPs, Ag-15nm, Ag-30nm, and Ag-55nm). Alveolar macrophages provide the first defense and were studied for their potential role in initiating oxidative stress. Cell exposure produced morphologically abnormal sizes and adherence characteristics with significant NP uptake at high doses after 24 h. Toxicity evaluations using mitochondrial and cell membrane viability along with reactive oxygen species (ROS) were performed. After 24 h of exposure, viability metrics significantly decreased with increasing dose (10−75 μg/mL) of Ag-15nm and Ag-30nm NPs. A more than 10-fold increase of ROS levels in cells exposed to 50 μg/mL Ag-15nm suggests that the cytotoxicity of Ag-15nm is likely to be mediated through oxidative stress. In addition, activation of the release of traditional inflammatory mediators were examined by measuring levels of cytokines/chemokines, including tumor necrosis factor (TNF-α), macrophage inhibitory protein (MIP-2), and interleukin-6 (IL-6), released into the culture media. After 24 h of exposure to Ag-15nm nanoparticles, a significant inflammatory response was observed by the release of TNF-α, MIP-2, and IL-1β. However, there was no detectable level of IL-6 upon exposure to silver nanoparticles. In summary, a size-dependent toxicity was produced by silver nanoparticles, and one predominant mechanism of toxicity was found to be largely mediated through oxidative stress.

Item Type:Article
Subjects:NanoSafety > Environment, health and safety aspects of nanotechnology
Biomedical Science > Nanotechnology for human health
ID Code:216
Deposited By:Lesley Tobin
Deposited On:21 Nov 2008 15:09
Last Modified:18 Feb 2009 17:52

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